The temperature, salinity, and alkalinity of Nostoc flagelliforme liquid culture were varied and the effects on the growth and physiological characteristics of the cells were studied. Modified BG-11 culture medium containing different concentrations of NaCl and Na2CO3 was used to culture N. flagelliforme cells at 25 ℃, 35 ℃, and 45 ℃, under light intensity of 80 μmol/(m2?s). Cell biomass of N. flagelliforme, plasmalemma permeability, and superoxide dismutase (SOD) activity, as well as the content of malondialdehyde (MDA), proline, soluble proteins, and soluble polysaccharides were determined at 8, 12, 16, and 24 h of incubation. The results indicated that, under high temperature and saline-alkali stress, the relative plasmalemma permeability of N. flagelliforme cells was increased by 193.2% and MDA content declined after an initial increase. With increase in the duration of treatment, SOD activity and proline content increased at first and then decreased. Soluble protein showed an upward trend, which was positively correlated with the duration of treatment. The soluble polysaccharide content declined after an initial increase. Compared with the growth rate of the control group, that of N. flagelliforme cells decreased significantly with theincrease in temperature and salinity-alkalinity. The results indicate that, during the process of artificial culture of N. flagelliforme in liquid medium with different levels of salinity and alkalinity at different incubation temperatures, soluble proteins and polysaccharides exert an important physiological effect. Thus, different temperatures and salinity-alkalinity can induce physiological response of N. flagelliforme.